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United States Patent |
5,739,241
|
Boeckh
,   et al.
|
April 14, 1998
|
Vinyl formate copolymers, preparation thereof, and use thereof in
detergents and cleaners
Abstract
Copolymers containing
(a) from 5 to 90 mol % of vinyl formate units,
(b) from 10 to 95 mol % of units of monoethylenically unsaturated
carboxylic acids,
(c) from 0 to 70 mol % of units of monoethylenically unsaturated
dicarboxylic acids, and
(d) from 0 to 30 mol % of units of other monoethylenically unsaturated
monomers
in copolymerized form and having K values of at least 8 (determined by the
method of H. Fikentscher in 1% strength by weight aqueous solution on the
sodium salt of the copolymers at pH 7 and 25.degree. C.), processes for
their preparation by copolymerizing monomer mixtures of
(a) from 5 to 90 mol % of vinyl formate,
(b) from 10 to 95 mol % of monoethylenically unsaturated carboxylic acids,
(c) from 0 to 70 mol % of monoethylenically unsaturated dicarboxylic acids,
and
(d) from 0 to 30 mol % of other monoethylenically unsaturated monomers
in an aqueous medium or in an organic solvent in the presence of
free-radical polymerization initiators and use of the vinyl formate
copolymers and of the vinyl alcohol copolymers obtainable therefrom by
hydrolysis and/or oxidation as detergent and cleaner additives.
Inventors:
|
Boeckh; Dieter (Limburgerhof, DE);
Kistenmacher; Axel (Ludwigshafen, DE);
Denzinger; Walter (Speyer, DE);
Ruhl; Thomas (Frankenthal, DE);
Funhoff; Angelika (Schriesheim, DE);
Baur; Richard (Mutterstadt, DE);
Kud; Alexander (Eppelsheim, DE);
Schwendemann; Volker (Neustadt, DE)
|
Assignee:
|
BASF Aktiengesellschaft (Ludwigshafen, DE)
|
Appl. No.:
|
750472 |
Filed:
|
December 16, 1996 |
PCT Filed:
|
May 31, 1995
|
PCT NO:
|
PCT/EP95/02053
|
371 Date:
|
December 16, 1996
|
102(e) Date:
|
December 16, 1996
|
PCT PUB.NO.:
|
WO95/34587 |
PCT PUB. Date:
|
December 21, 1995 |
Foreign Application Priority Data
| Jun 16, 1994[DE] | 44 20 920.7 |
Current U.S. Class: |
526/318.2; 526/318.4 |
Intern'l Class: |
C08F 022/02; C08F 020/10 |
Field of Search: |
526/318.2,318.4
|
References Cited
U.S. Patent Documents
4659793 | Apr., 1987 | Yang.
| |
4725655 | Feb., 1988 | Denzinger et al.
| |
Foreign Patent Documents |
1805007 | May., 1969 | DE | 526/318.
|
Primary Examiner: Schofer; Joseph L.
Assistant Examiner: Sarofin; N.
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Claims
We claim:
1. Vinyl formate copolymers containing
(a) from 5 to 90 mol % of vinyl formate units,
(b) from 10 to 95 mol % of units of monoethylenically unsaturated
carboxylic acids,
(c) from 0 to 70 mol % of units of monoethylenically unsaturated
dicarboxylic acids, and
(d) from 0 to 30 mol % of units of other monoethylenically unsaturated
monomers in copolymerized form and having K values of at least 8
(determined by the method of H. Fikentscher in 1% strength by weight
aqueous solution on the sodium salt of the copolymers at pH 7 and
25.degree. C.).
2. Vinyl formate copolymers as claimed in claim 1 containing
(a) from 25 to 75 mol % of vinyl formate units,
(b) from 20 to 70 mol % of units of monoethylenically unsaturated
carboxylic acids, and
(c) from 5 to 55 mol % of units of monoethylenically unsaturated
dicarboxylic acids in copolymerized form.
3. A process for preparing vinyl formate copolymers as claimed in claim 1
which comprises copolymerizing monomer mixtures of
(a) from 5 to 90 mol % of vinyl formate,
(b) from 10 to 95 mol % of monoethylenically unsaturated carboxylic acids,
(c) from 0 to 70 mol % of monoethylenically unsaturated dicarboxylic acids,
and
(d) from 0 to 30 mol % Of other monoethylenically unsaturated monomers in
an aqueous medium or in an organic solvent in the presence of free-radical
polymerization initiators.
4. A process as claimed in claim 3 wherein monomer mixtures of
(a) from 25 to 75 mol % of vinyl formate,
(b) from 20 to 70 mol % of monoethylenically unsaturated carboxylic acids,
and
(c) from 5 to 55 mol % of monoethylenically unsaturated dicarboxylic acids
are copolymerized in an aqueous medium in the presence of from 2 to 30% by
weight of peroxosulfates and/or hydroperoxides.
5. A process as claimed in claim 3, wherein the copolymerization is carried
out in the presence of from 0.05 to 30% by weight, based on the monomers,
of at least one surface-active agent.
6. A process as claimed in claim 5, wherein the surface-active agents used
are alkoxylated alcohols, alkoxylated phenols, alkoxylated a/nines or
alkoxylated carboxylic acids, alkyl sulfates, alkylsulfonates,
alkylbenzenesulfonates and/or block copolymers of ethylene oxide and
propylene oxide.
7. A composition, comprising the vinyl formate copolymer of claim 1 and a
detergent or cleaner.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vinyl formate copolymers, to processes for
preparing them by copolymerizing vinyl formate in the presence of
free-radical polymerization initiators, and to the use of the copolymers
as additives in detergents and cleaners.
DISCUSSION OF THE BACKGROUND
U.S. Pat. No. 3,268,491 discloses a process for preparing copolymers of
vinyl acetate and monoethylenically unsaturated dicarboxylic acids by
copolymerizing the monomers in an aqueous medium at pH 3-6 in the presence
of redox catalysts. The oxidizing component of the redox system is
preferably a persulfate, while the reducing component is a sulfite or a
thiosulfate. The oxidizing component is always used in molar excess
compared with the reducing component. The copolymers obtained are
alternating.
EP-A-0 441 022 discloses copolymers of monoethylenically unsaturated
dicarboxylic acids and monoethylenically unsaturated monocarboxylic acids,
which are prepared by copolymerizing from 3 to 25% by weight of at least
one monoethylenically unsaturated dicarboxylic acid and from 75 to 97% by
weight of at least one monoethylenically unsaturated monocarboxylic acid
and optionally carboxyl-free ethylenically unsaturated monomers in the
presence of water-soluble polymerization initiators, copper salts as
polymerization moderator and a base. Vinyl acetate is mentioned as
carboxyl-free ethylenically unsaturated monomer, but not exemplilied.
However, the polymerization conditions described are observed to lead to
considerable decomposition of the vinyl acetate or the formation of
homopolymers of vinyl acetate.
U.S. Pat. No. 3,887,480 describes the preparation of terpolymers containing
from 35 to 70 mol % of maleic acid, from 20 to 45 mol % of vinyl acetate
and from 2 to 40 mol % of acrylic acid in an aqueous medium in the
presence of from 18 to 40% by weight of persulfate and in the presence of
bisulfite, persulfate being used in molar excess over bisulfite.
In the above-described processes, the ethylenically unsaturated
dicarboxylic acids are at least partially neutralized, since otherwise
excessive decomposition of the vinyl acetate would occur during the
polymerization.
Since the vinyl formate is even quicker to hydrolyze than vinyl acetate,
the preparation of copolymers of vinyl formate is much more difficult than
the preparation of vinyl acetate copolymers.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide novel substances and to
devise additives for detergents and cleaners.
We have found that this object is achieved according to the present
invention by vinyl formate copolymers containing
(a) from 5 to 90 mol % of vinyl formate units,
(b) from 10 to 95 mol % of units of monoethylenically unsaturated
carboxylic acids,
(c) from 0 to 70 mol % of units of monoethylenically unsaturated
dicarboxylic acids, and
(d) from 0 to 30 mol % of units of other monoethylenically unsaturated
monomers
in copolymerized form and having K values of at least 8 (determined by the
method of H. Fikentscher in 1% strength by weight aqueous Solution on the
sodium salt of the copolymers at pH 7 and 25.degree. C.).
The present invention also provides a process for preparing vinyl formate
copolymers by copolymerizing monomer mixtures of
(a) from 5 to 90 mol % of vinyl formate,
(b) from 10 to 95 mol % of monoethylenically unsaturated carboxylic acids,
(c) from 0 to 70 mol % of monoethylenically unsaturated dicarboxylic acids,
and
(d) from 0 to 30 mol % of other monoethylenically unsaturated monomers
in an aqueous medium or in an organic solvent in the presence of
free-radical polymerization initiators.
The present invention further provides for the use of the vinyl formate
copolymers and of the vinyl alcohol copolymers obtainable therefrom by
hydrolysis and/or oxidation as detergent and cleaner additives.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The monomer mixtures used for preparing the copolymers comprise vinyl
formate as monomer of group (a) and at least one monoethylenically
unsaturated monocarboxylic acid as monomer of group (b). Said monomers (b)
are derived for example from monoethylenically unsaturated monocarboxylic
acids having from 3 to 8, preferably from 3 to 5, carbon atoms in the
molecule. Examples thereof are acrylic acid, methacrylic acid, vinylacetic
acid and crotonic acid. The preferred monomers of this group are acrylic
acid, methacrylic acid and mixtures of acrylic acid and methacrylic acid
in any desired ratio.
The copolymers of the present invention contain units of monoethylenically
unsaturated carboxylic acids in amounts from 10 to 95, preferably from 20
to 70, mol %.
The monomers of group (c) are monoethylenically unsaturated dicarboxylic
acids. Such dicarboxylic acids have for example from 4 to 8 carbon atoms
in the molecule. Examples of monomers (c) are maleic acid, fumaric acid,
itaconic acid and citraconic acid. A dicarboxylic acid of this type which
is capable of forming an anhydride can also be used in the form of the
anhydride. If monomers (c) are present at all in the Copolymerization,
preference is given to using maleic acid or maleic anhydride. The
copolymers contain units of monomers (c) in amounts from 0 to 70,
preferably from 5 to 55, mol %.
Preference is given to copolymers containing
(a) from 25 to 75 mol % of vinyl formate units,
(b) from 20 to 70 mol % of units of monoethylenically unsaturated
carboxylic acids, and
(c) from 5 to 55 mol % of units of monoethylenically unsaturated
dicarboxylic acids in copolymerized form.
The monomer mixtures may optionally comprise (d) other copolymerizable
monoethylenically unsaturated monomers, for example acrylamide,
methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic
acid, allylsulfonic acid, methallylsulfonic acid, vinylphosphonic acid,
allylphosphonic acid, acrylonitrile, methacrylonitrile, dimethylaminoethyl
acrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate,
n-vinylpyrrolidone, n-vinylformamide, n-vinylimidazole,
n-vinylimidazoline, 1-vinyl-2-methylimidazole, 1-vinyl-2-methylimidazoline
and hydroxyalkyl esters having from 2 to 6 carbon atoms in the
hydroxyalkyl group with monoethylenically unsaturated carboxylic acids
having from 3 to 6 carbon atoms, such as hydroxyethyl acrylate,
hydroxyethyl methacrylate, hydroxy-n-propyl acrylate, hydroxyisopropyl
acrylate, hydroxyisobutyl acrylate, hydroxyethyl monomaleate,
1,4-butanediol monoacrylate and hydroxy-n-butyl dimaleate. The monomers of
group (d) are used in the copolymerization in amounts from 0 to 30 mol %.
If these monomers are used for modifying the copolymers, they are
preferably used in amounts from 5 to 20 mol %.
The copolymerization of said monomers (a) and (b) and optionally (c) and/or
(d) is carried out in an aqueous medium or in an organic solvent. For the
purposes of the present invention, an aqueous medium comprehends water as
sole solvent and mixtures of water with up to 50% by weight of other
solvents miscible therewith. Water-miscible solvents include for example
dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol
dimethyl ›sic! ether, diethylene glycol dimethyl ether, acetone, methyl
ethyl ketone, sublohexanone ›sic!, methylglycol acetate and also the
monohydric C.sub.1 - to C.sub.4 -alcohols such as methanol, ethanol,
isopropanol, n-butanol, sec-butanol, tert-butanol and ethylene glycol.
The copolymerization can for example also be carried out as a precipitation
polymerization in C.sub.1 -C.sub.3 -alkylbenzenes, aliphatic, acyclic
C.sub.4 -C.sub.8 -ketones, chlorinated C.sub.1 -C.sub.4 -alkanes or
mixtures thereof. Specific examples of inert organic solvents suitable for
a precipitation polymerization are:
benzene, toluene, p-xylene, m-xylene, o-xylene and their technical grade
mixtures, ethylbenzene, diethylbenzene, methylethylbenzene, methylene
chloride, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,1-trichloroethane,
1,1,2-trichloroethane, perchloroethylene, 1,2-dichloropropane, butyl
chloride, fluorinated hydrocarbons, 2-butanone, 3-pentanone and also
3-hexanone.
The copolymerization can also be carried out as a solution polymerization
in at least one of the abovementioned ethers or ketones or in methylglycol
acetate, ethylglycol acetate and also monohydric C.sub.1 -C.sub.4
-alcohols. If dicarboxylic anhydrides are used as monomers of group (c),
the copolymerization is preferably carried out in the absence of alcohols,
so that the copolymers formed have anhydride groups which are accessible
to further chemical reactions.
Said monomers (a) and (b) and optionally (c) and/or (d) can also be
copolymerized with one another in the form of a suspension polymerization
in at least one aliphatic hydrocarbon. Examples of suitable aliphatic
hydrocarbons include pentane, hexane, heptane, octane, isooctane,
cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane,
diethylcyclohexane and mixtures thereof. Of the contemplated aliphatic
hydrocarbons, all the isomers or mixtures can be used.
A precipitation or suspension copolymerization is advantageously carried
out in the additional presence of protective colloids. Examples of
suitable protective colloids include copolymers of maleic anhydride and
vinyl alkyl ethers which have from 1 to 20 carbon atoms in the alkyl group
or copolymers of maleic anhydride and olefins having from 8 to 20 carbon
atoms and their monoesters with C.sub.10 -C.sub.20 -alcohols or monoamides
with C.sub.10 -C.sub.20 -amines. Also suitable for use as protective
colloid are polyalkyl vinyl ethers Whose alkyl group contains from 1 to 20
carbon atoms. If a protective colloid is used in the copolymerization, the
amounts customarily range from 0.05 to 4% by weight, based on the monomers
to be polymerized.
In a preferred embodiment, the copolymerization is carried out in water or
in mixtures of water and water-miscible solvents such as ethanol,
n-propanol, methanol, ethylene glycol, oligomeric water-soluble alkylene
glycols and ethoxylated C.sub.1 -C.sub.18 -alcohols with 1-20 ethylene
oxide groups, isopropanol, acetone, methyl ethyl ketone, tetrahydrofuran
and dioxane.
The copolymerization can be carried out batchwise, semicontinuously or
continuously in suitable reactors. The polymerization can be initiated by
a single addition of a polymerization initiator and optionally a
coinitiator, or the initiator and/or the coinitiator are added portionwise
or continuously to the copolymerization mixture during the
copolymerization. The copolymerization is preferably carried out batchwise
in stirred kettles, in which case a small amount of the mixture to be
polymerized, for example 5%, is initially charged and the rest of the
monomers are added to the kettle continuously or batchwise under constant
thorough mixing. The copolymerization is customarily carried out under an
inert gas atmosphere, for example under nitrogen. Vinyl formate is
preferably metered into the copolymerization mixture in the course of the
copolymerization. It is of course also possible to introduce vinyl formate
as initial charge and to meter in the other comonomers.
The copolymerization is carried out for example at temperatures from
10.degree. to 150.degree. C., preferably at from 20.degree. to 100.degree.
C. If the copolymerization temperatures are above the boiling point of the
reaction mixture, the copolymerization is carried out under
superatmospheric pressure in suitable apparatus, for example pressure
kettles or stirrable autoclaves..In most cases, the copolymerization is
carried out under atmospheric pressure at from 30.degree. to 70.degree. C.
The polymerization initiator can be basically any customary compound for
this purpose which forms free radicals under the conditions of the
polymerization, eg. peroxides, hydroperoxides, peroxodisulfates,
percarbonates, peroxyesters, hydrogen peroxide and azo compounds. Examples
of initiators, which can be soluble or insoluble in water, are hydrogen
peroxide, dibenzoyl peroxide, dicyclohexyl peroxodicarbonate, dilauryl
peroxide, methyl ethyl ketone peroxide, acetylacetone peroxide, tert-butyl
hydroperoxide, cumene hydroperoxide, tert-butyl perneodecanoate, tert-amyl
perpivalate, tert-butyl perpivalate, tert-butyl perneohexanoate,
tert-butyl per -2-ethylhexanoate, tert-butyl. perbenzoate, lithium
peroxodisulfate, sodium peroxodisufate, potassium peroxodisulfate,
ammonium peroxodisulfate, azodiisobutyronitrile,
2,2'-azobis(2-amidinopropane) dihydrochloride,
2,2'-azobis(N,N'-dimethylene)isobutyramidine dihydrochloride,
2-(carbamoylazo)isobutyronitrile and 4,4'-azobis(4-cyanovaleric acid).
The initiators can be used alone or mixed with one another, for example
mixtures of hydrogen peroxide and sodium peroxodisulfate. If the
polymerization is carried out in an aqueous medium, water-soluble
initiators are preferred. Similarly, the known redox catalysts can be
used. Such systems comprise for example at least one of the
above-described peroxide compounds in combination with a reducing agent,
for example reducing sulfur or phosphorus compounds, eg. bisulfites,
sulfites, thiosulfates, dithionites and tetrathionates of alkali metals
and ammonium compounds, sodium hypophosphite, phosphorous acid and
phosphites such as sodium phosphite, potassium phosphite, and ammonium
phosphite. Sulfur dioxide may also be used as reducing sulfur compound.
Further reducing agents for redox catalysts include for example ascorbic
acid, formic acid and aldehydes, such as formaldehyde or acetaldehyde.
The redox catalysts may additionally comprise salts of transition metals,
for example salts of iron, cobalt, nickel, copper, vanadium and manganese.
Suitable salts include for example iron(II) sulfate, cobalt(II) chloride,
nickel(II) sulfate, copper(I) chloride, manganese(II) acetate,
vanadium(III) acetate and manganese(II) chloride. The known redox
catalysts may comprise the reducing component in a molar ratio of from
0.05 to 1 mol per mole of the oxidizing component. The heavy metal ions
are customarily used in amounts from 0.1 ppm to 0.2%, based on the redox
initiator.
The initiators are generally used in amounts from 0.05 to 30, preferably
from 1 to 15, % by weight, based on the monomers to be polymerized. If the
polymerization is carried out in an aqueous medium, preference is given to
using redox catalysts, in which case, based on the monomers to be
polymerized, from 0.5 to 25% by weight of at least one peroxide initiator
and from 0.05 to 30% by weight of at least one reducing agent are used.
Preference is given to combinations of peroxodisulfates with alkali metal
or ammonium bisulfites. For example, based on the monomers to be
polymerized, from 1 to 15% by weight of sodium peroxodisulfate or
potassium peroxodisulfate and from 0.5 to 25% by weight of sodium
bisulfite or potassium bisulfite are used. To prepare polymers which are
particularly low in residual monomer, from 2 to 10% by weight of
peroxodisulfate and from 2 to 20% by weight of bisulfite are used, based
on the monomers to be polymerized.
If the copolymerization is carried out in an organic solvent, initiators
are used which are soluble in the organic solvent, for example
acetylcyclohexanesulfonyl peroxide, diacetylperoxydicarbonate,
dicyclohexyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate,
tert-butyl perneodecanoate, tert-butyl perpivalate, dilauroyl peroxide,
2,2'-azobis(2,4-dimethylvaleronitrile), tert-butyl per-2-ethylhexanoate,
tert-butyl peracetate, di-tert-peroxide ›sic!, cumene hydroperoxide and/or
tert-butyl hydroperoxide.
Acidic monomers may be used in the copolymerization in partly neutralized
form. The degree of neutralization may range for example from 5 to 75% and
is usually within the range from 10 to 50% by weight. Particular
preference is given to degrees of neutralization below 25%. The acidic
monomers are neutralized for example with alkali metal, alkaline earth
metal and ammonium bases, for example with sodium hydroxide solution,
potassium hydroxide solution, ammonia, magnesium oxide, calcium oxide,
calcium hydroxide, sodium carbonate, sodium bicarbonate, potassium
carbonate or barium oxide.
Preference is given to the copolymerization of monomer mixtures of
(a) from 25 to 75 mol % of vinyl formate,
(b) from 20 to 70 mol % of monoethylenically unsaturated carboxylic acids,
and
(c) from 5 to 55 mol % of monoethylenically unsaturated dicarboxylic acids
in an aqueous medium in the presence of from 2 to 30% by weight of
peroxosulfates and/or hydroperoxides. The copolymerization in an aqueous
medium or in pure water as solvent is preferably carried out in the
presence of from 0.05 to 30, preferably from 0.5 to 15, % by weight of a
surface-active agent. The addition of a surface-active agent to the
polymerization mixture promotes the uniform incorporation of the vinyl
formate into the copolymer and at the same time counteracts the
decomposition of vinyl formate into formic acid and acetaldehyde.
A suitable surface-active agent is any compound which reduces the surface
tension of water. Such compounds are customarily used as emulsifiers in
emulsion polymerization. Examples of suitable surface-active agents
include alkoxylated alcohols, alkoxylated phenols, alkoxylated amines,
alkoxylated carboxylic acids, alkylpolyglycoside, alkyl sulfates,
alkylsulfonates, alkylbenzenesulfonates and/or block copolymers of
ethylene oxide and propylene oxide.
Particularly suitable alkoxylated alcohols are prepared for example by
ethoxylating alcohols having from 8 to 22 carbon atoms, for which both
natural and synthetic alcohols can be used. The alcohols can be
straight-chain or branched and may still contain hydroxyl groups or else
one or more monoethylenically unsaturated double bonds. The alcohol
ethoxylates may contain from 2 to 50, preferably from 3 to 25, mol of
ethylene oxide per mole of alcohol. It is also possible to use block
copolymers which are obtainable by stagewise alkoxylation of alcohols
with, for example, ethylene oxide and then propylene oxide and optionally
butylene oxide. The arrangement of the alkylene oxide blocks therein is
optional. The addition of alkylene oxides to alcohols can also be carried
out with a mixture of alkylene oxides, producing random alkoxylates.
The same principle produces the other alkoxylated compounds by adding at
least one alkylene oxide to alkylphenols, amines or carboxylic acids. The
alkylphenols customarily contain from 1 to 12 carbon atoms in the alkyl
group. The amines may contain for example one or more amino groups in the
molecule and have from 8 to 22 carbon atoms.
The carboxylic acids to be alkoxylated preferably have from 8 to 22 carbon
atoms in the molecule.
Alkyl sulfates and alkylsulfonates, like the other surface-active agents
mentioned, are commercially available. In most cases the alkyl group
contains from 12 to 16 carbon atoms. The alkyl group of the
alkylbenzenesulfonates is derived for example from straight-chain or
branched alkyl radicals having from 8 to 16 carbon atoms. Suitable block
copolymers of ethylene oxide and propylene oxide may have for example
number average molecular weights from 300 to 10,000.
In most cases the surface-active agents are used in amounts from 0.75 to
10% by weight, based on the monomers. The amount of water or organic
solvent is chosen for example to obtain polymer solutions or suspensions
having a concentration of from 10 to 80, preferably from 30 to 70, % by
weight of polymer.
At high concentration, the copolymers can precipitate from the solutions.
However, by neutralizing with alkali metal bases or ammonia they can be
redissolved or at least brought into a stable and homogeneous dispersion.
The copolymers have for example K values from 10 to 120, usually from 10
to 70 (determined by the method of H. Fikentscher in 1% strength by weight
aqueous solution on the sodium salt of the copolymers at pH 7 and
25.degree. C.).
The vinyl formate copolymers may be modified by solvolysis and/or
oxidation. To hydrolyze the copolymers, for example, the as-copolymerized
solutions can be brought with sodium hydroxide or potassium hydroxide
solution to a pH above 8 and the hydrolysis of the vinyl formate units in
the copolymer into vinyl alcohol units may be speeded up, if necessary, by
raising the temperature of the solution to, for example, 100.degree. C.
The hydrolysis may be partial, for example from 5 to 90%, or else be
carried on to completion. The K value of the hydrolyzed copolymers is
likewise within the range from 10 to 120.
The copolymers may, if desired, also be oxidized, in which case a reduction
in the molecular weight is observed in most cases. Accordingly, the
oxidized copolymers will have a different K value too. Their K value can
be for example from 2 to 50 units below the K value of the
as-copolymerized copolymers. The oxidation of the copolymers is preferably
carried out in aqueous solution. The oxidizing agent used can be any
compound which gives off active oxygen, for example alkaline hypochlorite
solutions, ozone or hydrogen peroxide. The oxidation can be carried out
for example at temperatures from 10.degree. to 100.degree. C. Since the
oxidation is preferably carried out in an alkaline medium, the copolymers
are also observed to undergo a more or less pronounced hydrolysis. The
amount of the at least one oxidizing agent used in the oxidative
aftertreatment of the copolymers ranges for example from 0.1 to 30,
preferably from 2.5 to 25, % by weight, based on the copolymers. The
oxidative treatment has the effect of improving the dispersing properties
of the copolymers.
The copolymers obtainable by the process of the present invention and the
vinyl alcohol copolymers obtainable therefrom by hydrolysis and/or
oxidation are used as detergent and cleaner additives. In
reduced-phosphate (phosphate content <25% by weight) and phosphate-free
formulations, they have a marked incrustation-inhibiting effect and may be
present therein in amounts from 0.1 to 30, preferably from 1 to 15, % by
weight, based on the particular formulation.
The detergents and cleaners comprise at least one surfactant with or
without other customary ingredients. Preference is given to using
surfactants which are biodegradable.
The detergents can be pulverulent or else liquid. The compositions of
detergent and cleaner formulations can vary greatly. Detergent and cleaner
formulations customarily contain from 2 to 50% by weight of surfactants
with or without builders. These figures apply not only to liquid but also
to pulverulent detergents. Detergent and cleaner formulations customary in
Europe, the U.S. and Japan are given for example in table form in Chemical
and Engn. News 67 (1989), 35. Further details about the compositions of
detergents and cleaners can be found in WO-A-90/13581 and in Ullmann's
Encyklopadie der technischen Chemie, Verlag Chemie, Weinheim, 1983, 4th
Edition, pages 63-160. The detergents may additionally contain a bleaching
agent, for example sodium perborate, which if used may be present in the
detergent formulation in amounts of up to 30% by weight. The detergents
and cleaners may contain further customary additives, for example
complexing agents, opacifiers, optical brighteners, enzymes, perfume oils,
color transfer inhibitors, grayness inhibitors, soil release polymers
and/or bleach activators.
The K values of the copolymers were determined by the method of H.
Fikentscher, Cellulose-Chemie 13 (1932), 58-64, 71-74, in aqueous solution
on the sodium salts of the copolymers at a concentration of 1% by weight,
a pH of 7 and a temperature of 25.degree. C.
The percentages in the Examples are by weight.
EXAMPLES
Example 1
A stirred 2 l glass reactor equipped with a horseshoe stirrer and 4 add
vessels was charged with 49.1 g of maleic anhydride together with 18.0 g
of a 20% strength aqueous solution of an addition product of 25 mol of
ethylene oxide with isooctylphenol and 10.3 g of a 35% strength aqueous
solution of the sulfate of an addition product of 125 mol of ethylene
oxide with isooctylphenol in 190 ml of water, followed by 20.2 g of 50%
strength sodium hydroxide solution for partial neutralization, and heated
to an internal temperature of 45.degree. C. with an inert gas atmosphere.
To this solution were added 180 g of vinyl formate and 144.2 g of acrylic
acid as separate feeds over 5 h. Starting at the same time, the metered
addition over 6 h was commenced of a solution of 18.7 g of sodium
peroxodisulfate in 168.3 ml of water and 28.0 g of sodium bisulfite in 250
ml of water. All the while the temperature of the reaction mixture was
held at 45.degree. C. On completion of the stream additions the reaction
mixture was heated at 45.degree. C. for a further 2 h. The solution was
cooled down to room temperature and adjusted with sodium hydroxide
solution to pH 7 with cooling. The polymer had a K value of 50.4.
Example 2
A stirred 2 l glass reactor equipped with a horseshoe stirrer and 4 add
vessels was charged with 98.7 g of maleic anhydride together with 12.5 g
of a 20% strength aqueous solution of an addition product of 25 mol of
ethylene oxide with isooctylphenol and 7.2 g of a 35% strength aqueous
solution of the sulfate of an addition product of 25 mol of ethylene oxide
with isooctylphenol in 190 ml of water, followed by 80.5 g of 50% strength
sodium hydroxide solution for partial neutralization, and heated to an
internal temperature of 45.degree. C. with an inert gas atmosphere. To
this solution were added 125.2 g of vinyl formate and 175.3 g of acrylic
acid as separate feeds over 5 h. Starting at the same time, the metered
addition over 6 h was commenced of a solution of 20.4 g of sodium
peroxodisulfate in 183.8 ml of water and 28.0 g of sodium bisulfite in 263
ml of water. All the while the internal temperature of the reaction
mixture was held at 45.degree. C. On completion of the stream additions
the reaction mixture was heated at 45.degree. C. for a further 2 h. The
solution was cooled down to room temperature and adjusted with sodium
hydroxide solution to pH 7 with cooling. The polymer had a K value of
37.4.
Example 3
A stirred 2 l glass reactor equipped with a horseshoe stirrer and 4 add
vessels was charged with 56.4 g of maleic anhydride together with 25.0 g
of a 20% strength aqueous solution of an addition product of 25 mol of
ethylene oxide with isooctylphenol and 14.3 g of a 35% strength aqueous
solution of the sulfate of an addition product of 25 mol of ethylene oxide
with isooctylphenol in 190 ml of water, followed by 46.0 g of 50% strength
sodium hydroxide solution for partial neutralization, and heated to an
internal temperature of 45.degree. C. with an inert gas atmosphere. To
this solution were added 250 g of vinyl formate and 100.2 g of acrylic
acid as separate feeds over 5 h. Starting at the same time, the metered
addition over 6 h was commenced of a solution of 20.4 g of sodium
peroxodisulfate in 183.8 ml of water and 28.0 g of sodium bisulfite in 263
ml of water. All the while the internal temperature of the reaction
mixture was held at 45.degree. C. On completion of the stream additions
the reaction mixture was heated at 45.degree. C. for a further 2 h. The
solution was cooled down to room temperature and adjusted with sodium
hydroxide solution to pH 7 with cooling. The polymer had a K value of
41.7.
Example 4
A stirred 2 l glass reactor is charged with a solution of 138.2 g of maleic
anhydride in 518.1 g of xylene under a blanket of nitrogen. The initial
charge is heated to 85.degree. C. To this solution is added over 2 h a
solution of 100.8 g of acrylic acid and 100.8 g of vinyl formate in 221.2
g of xylene. At the same time the metered addition over 3 h is commenced
of a solution of 7.11 g of tert-butyl per-2-ethylenehexanoate ›sic! in
92.9 g of xylene. During the polymerization the internal temperature is
held at 80.degree. C. On completion of the stream additions the reaction
mixture is heated at 80.degree. C. for a further hour. The polymer formed
is separated off by filtration and dried.
Example 5
100 g of the polymer of Example 4 are admixed with 200 ml of fully
demineralized water and heated to the boil for 2 h. The solution is then
neutralized with 94 g of sodium hydroxide solution (50%). The polymer had
a K value of 39.7.
Example 6
A stirred 2 l glass reactor is charged with a solution of 137.2 g of maleic
anhydride in 520.5 g of tetrahydrofuran under a blanket of nitrogen. The
initial charge is heated to 65.degree. C. To this solution is added over 2
h a solution of 100.8 g of acrylic acid and 100.8 g of vinyl formate in
221.2 g of tetrahydrofuran. At the same time, the metered addition over 3
h is commenced of a solution of 9.48 g of tert-butyl perpivalate ›lacuna!
90.5 g of tetrahydrofuran. During the polymerization the internal
temperature is held at 65.degree. C. On completion of the stream additions
the reaction mixture is heated at 65.degree. C. for a further hour. Steam
is introduced to distill tetrahydrofuran off as an azeotrope. The aqueous
solution of the terpolymer obtained is adjusted to pH 7 with sodium
hydroxide solution. The polymer had a K value of 15.6.
Use Examples
The incrustation-inhibiting properties of the polymers were determined in a
wash test. In each case test fabrics made of cotton were washed. The
number of wash cycles was 15. Following this number of washes, the ash
content of the test fabric was determined by ashing. The lower the ash
content after repeated washing, the greater the effectiveness of the
polymer as an incrustation inhibitor. The ash values obtained are
indicated in Table 3. The copolymers of the present invention show
distinct effectiveness over Comparative Example 1 (no polymer) and
Comparative Example 2 featuring a commercially available copolymer as
incrustation inhibitor. The polymers of the present invention show in some
instances distinct improvements over the standard.
TABLE 1
______________________________________
Wash conditions
Washing apparatus Launderometer
______________________________________
Wash liquor 250 g
Detergent dosage 6 g/l
Wash time 30 min
Wash temperature 60.degree. C.
Liquor ratio 12.5:1
Number of wash cycles
15
Test fabric 20 g of woven cotton
______________________________________
TABLE 2
______________________________________
Detergent composition
% by weight
______________________________________
Alkylbenzenesulfonate 8.00
C.sub.13 /C.sub.15 Oxo alcohol ethoxylated with 7 EO .sup.1)
7.00
Fatty acid, sodium salt 2.00
Carboxymethylcellulose 1.00
Zeolite A (Wessalith P) 36.00
Sodium carbonate 12.00
Sodium perborate * 3 H.sub.2 O
22.0
TAED .sup.2) 2.00
Optical brightener 0.20
Enzymes 0.50
Polymer (test substrate)
5.00
Sodium sulfate remainder to 100
______________________________________
.sup.1) EO = ethylene oxide
.sup.2) TAED = tetraacetylethylenediamine
The results of the wash trials are reproduced in Table 3:
TABLE 3
______________________________________
Wash series
Comparative
Example Example Polymer Ash
No. No. No. ›%!
______________________________________
7 -- 1 2.1
-- 1 -- 3.2
8 -- 6 0.8
-- 2 AA/MA .sup.3)
2.2
______________________________________
.sup.3) copolymer of acrylic acid and maleic acid in a weight ratio of
70:30 with a K value (measured on the sodium salt in 1% strength aqueous
solution) of 60.
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